Drop the redundant "Lock" suffix from LWLock wait event names.

This was mostly confusing, especially since some wait events in
this class had the suffix and some did not.

While at it, stop exposing MainLWLockNames[] as a globally visible
name; any code using that directly is almost certainly wrong, as
its name has been misleading for some time.
(GetLWLockIdentifier() is what to use instead.)

Discussion: https://postgr.es/m/28683.1589405363@sss.pgh.pa.us

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index e5b21cd8f61f9c05ce4e512f737e96cb41be44e8..42755659e1b3a712d3754feb43f072509fb48c87 100644 (file)
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -1750,31 +1750,31 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
 
     
      
-      AddinShmemInitLock
+      AddinShmemInit
       Waiting to manage an extension's space allocation in shared
        memory.
      
      
-      AutoFileLock
+      AutoFile
       Waiting to update the postgresql.auto.conf
        file.
      
      
-      AutovacuumLock
+      Autovacuum
       Waiting to read or update the current state of autovacuum
        workers.
      
      
-      AutovacuumScheduleLock
+      AutovacuumSchedule
       Waiting to ensure that a table selected for autovacuum
        still needs vacuuming.
      
      
-      BackgroundWorkerLock
+      BackgroundWorker
       Waiting to read or update background worker state.
      
      
-      BtreeVacuumLock
+      BtreeVacuum
       Waiting to read or update vacuum-related information for a
        B-tree index.
      
@@ -1792,15 +1792,15 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        pool.
      
      
-      CheckpointLock
+      Checkpoint
       Waiting to begin a checkpoint.
      
      
-      CheckpointerCommLock
+      CheckpointerComm
       Waiting to manage fsync requests.
      
      
-      CommitTsLock
+      CommitTs
       Waiting to read or update the last value set for a
        transaction commit timestamp.
      
@@ -1809,16 +1809,16 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting for I/O on a commit timestamp SLRU buffer.
      
      
-      CommitTsSLRULock
+      CommitTsSLRU
       Waiting to access the commit timestamp SLRU cache.
      
      
-      ControlFileLock
+      ControlFile
       Waiting to read or update the pg_control
        file or create a new WAL file.
      
      
-      DynamicSharedMemoryControlLock
+      DynamicSharedMemoryControl
       Waiting to read or update dynamic shared memory allocation
        information.
      
@@ -1833,12 +1833,12 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        about heavyweight locks.
      
      
-      LogicalRepWorkerLock
+      LogicalRepWorker
       Waiting to read or update the state of logical replication
        workers.
      
      
-      MultiXactGenLock
+      MultiXactGen
       Waiting to read or update shared multixact state.
      
      
@@ -1846,7 +1846,7 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting for I/O on a multixact member SLRU buffer.
      
      
-      MultiXactMemberSLRULock
+      MultiXactMemberSLRU
       Waiting to access the multixact member SLRU cache.
      
      
@@ -1854,11 +1854,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting for I/O on a multixact offset SLRU buffer.
      
      
-      MultiXactOffsetSLRULock
+      MultiXactOffsetSLRU
       Waiting to access the multixact offset SLRU cache.
      
      
-      MultiXactTruncationLock
+      MultiXactTruncation
       Waiting to read or truncate multixact information.
      
      
@@ -1867,20 +1867,20 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        buffer.
      
      
-      NotifyQueueLock
+      NotifyQueue
       Waiting to read or update NOTIFY messages.
      
      
-      NotifySLRULock
+      NotifySLRU
       Waiting to access the NOTIFY message SLRU
        cache.
      
      
-      OidGenLock
+      OidGen
       Waiting to allocate a new OID.
      
      
-      OldSnapshotTimeMapLock
+      OldSnapshotTimeMap
       Waiting to read or update old snapshot control information.
      
      
@@ -1922,24 +1922,24 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        serializable transactions.
      
      
-      ProcArrayLock
+      ProcArray
       Waiting to access the shared per-process data structures
        (typically, to get a snapshot or report a session's transaction
        ID).
      
      
-      RelationMappingLock
+      RelationMapping
       Waiting to read or update
        a pg_filenode.map file (used to track the
        filenode assignments of certain system catalogs).
      
      
-      RelCacheInitLock
+      RelCacheInit
       Waiting to read or update a pg_internal.init
        relation cache initialization file.
      
      
-      ReplicationOriginLock
+      ReplicationOrigin
       Waiting to create, drop or use a replication origin.
      
      
@@ -1948,11 +1948,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        origin.
      
      
-      ReplicationSlotAllocationLock
+      ReplicationSlotAllocation
       Waiting to allocate or free a replication slot.
      
      
-      ReplicationSlotControlLock
+      ReplicationSlotControl
       Waiting to read or update replication slot state.
      
      
@@ -1965,22 +1965,22 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        buffer.
      
      
-      SerializableFinishedListLock
+      SerializableFinishedList
       Waiting to access the list of finished serializable
        transactions.
      
      
-      SerializablePredicateListLock
+      SerializablePredicateList
       Waiting to access the list of predicate locks held by
        serializable transactions.
      
      
-      SerializableXactHashLock
+      SerializableXactHash
       Waiting to read or update information about serializable
        transactions.
      
      
-      SerialSLRULock
+      SerialSLRU
       Waiting to access the serializable transaction conflict SLRU
        cache.
      
@@ -1995,16 +1995,16 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        query.
      
      
-      ShmemIndexLock
+      ShmemIndex
       Waiting to find or allocate space in shared memory.
      
      
-      SInvalReadLock
+      SInvalRead
       Waiting to retrieve messages from the shared catalog invalidation
        queue.
      
      
-      SInvalWriteLock
+      SInvalWrite
       Waiting to add a message to the shared catalog invalidation
       queue.
      
@@ -2013,29 +2013,29 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting for I/O on a sub-transaction SLRU buffer.
      
      
-      SubtransSLRULock
+      SubtransSLRU
       Waiting to access the sub-transaction SLRU cache.
      
      
-      SyncRepLock
+      SyncRep
       Waiting to read or update information about the state of
        synchronous replication.
      
      
-      SyncScanLock
+      SyncScan
       Waiting to select the starting location of a synchronized table
        scan.
      
      
-      TablespaceCreateLock
+      TablespaceCreate
       Waiting to create or drop a tablespace.
      
      
-      TwoPhaseStateLock
+      TwoPhaseState
       Waiting to read or update the state of prepared transactions.
      
      
-      WALBufMappingLock
+      WALBufMapping
       Waiting to replace a page in WAL buffers.
      
      
@@ -2043,7 +2043,7 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting to insert WAL data into a memory buffer.
      
      
-      WALWriteLock
+      WALWrite
       Waiting for WAL buffers to be written to disk.
      
      
@@ -2051,16 +2051,16 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       Waiting for I/O on a transaction status SLRU buffer.
      
      
-      XactSLRULock
+      XactSLRU
       Waiting to access the transaction status SLRU cache.
      
      
-      XactTruncationLock
+      XactTruncation
       Waiting to execute pg_xact_status or update
        the oldest transaction ID available to it.
      
      
-      XidGenLock
+      XidGen
       Waiting to allocate a new transaction ID.
      
     

diff --git a/src/backend/storage/lmgr/generate-lwlocknames.pl b/src/backend/storage/lmgr/generate-lwlocknames.pl
index 50fb8625cad9a1304064c983f53c9fedb0f55d5e..ca54acdfb0f88b8cbc18d070481a0e6adb94dbe9 100644 (file)
--- a/src/backend/storage/lmgr/generate-lwlocknames.pl
+++ b/src/backend/storage/lmgr/generate-lwlocknames.pl
@@ -23,7 +23,7 @@ print $h $autogen;
 print $h "/* there is deliberately not an #ifndef LWLOCKNAMES_H here */\n\n";
 print $c $autogen, "\n";
 
-print $c "const char *const MainLWLockNames[] = {";
+print $c "const char *const IndividualLWLockNames[] = {";
 
 while (<$lwlocknames>)
 {
@@ -38,6 +38,10 @@ while (<$lwlocknames>)
 
    (my $lockname, my $lockidx) = ($1, $2);
 
+   my $trimmedlockname = $lockname;
+   $trimmedlockname =~ s/Lock$//;
+   die "lock names must end with 'Lock'" if $trimmedlockname eq $lockname;
+
    die "lwlocknames.txt not in order"   if $lockidx < $lastlockidx;
    die "lwlocknames.txt has duplicates" if $lockidx == $lastlockidx;
 
@@ -47,7 +51,7 @@ while (<$lwlocknames>)
        printf $c "%s   \"\"", $continue, $lastlockidx;
        $continue = ",\n";
    }
-   printf $c "%s   \"%s\"", $continue, $lockname;
+   printf $c "%s   \"%s\"", $continue, $trimmedlockname;
    $lastlockidx = $lockidx;
    $continue    = ",\n";
 

diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index 0bdc8e0499da33b416bd24d26efd8987d89d8de9..2fa90cc0954d9e58f311c18d0e7e402ec900f16e 100644 (file)
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -111,7 +111,7 @@ extern slock_t *ShmemLock;
  * There are three sorts of LWLock "tranches":
  *
  * 1. The individually-named locks defined in lwlocknames.h each have their
- * own tranche.  The names of these tranches appear in MainLWLockNames[]
+ * own tranche.  The names of these tranches appear in IndividualLWLockNames[]
  * in lwlocknames.c.
  *
  * 2. There are some predefined tranches for built-in groups of locks.
@@ -125,6 +125,7 @@ extern slock_t *ShmemLock;
  * All these names are user-visible as wait event names, so choose with care
  * ... and do not forget to update the documentation's list of wait events.
  */
+extern const char *const IndividualLWLockNames[];  /* in lwlocknames.c */
 
 static const char *const BuiltinTrancheNames[] = {
    /* LWTRANCHE_XACT_BUFFER: */
@@ -781,7 +782,7 @@ GetLWTrancheName(uint16 trancheId)
 {
    /* Individual LWLock? */
    if (trancheId < NUM_INDIVIDUAL_LWLOCKS)
-       return MainLWLockNames[trancheId];
+       return IndividualLWLockNames[trancheId];
 
    /* Built-in tranche? */
    if (trancheId < LWTRANCHE_FIRST_USER_DEFINED)

diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index d8e1b5c493eb707a0910503c18e0e5249fe7eec3..c04ae971485e311c741c6332232382e39573422f 100644 (file)
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -88,7 +88,6 @@ typedef union LWLockMinimallyPadded
 } LWLockMinimallyPadded;
 
 extern PGDLLIMPORT LWLockPadded *MainLWLockArray;
-extern const char *const MainLWLockNames[];
 
 /* struct for storing named tranche information */
 typedef struct NamedLWLockTranche